Métodos de inoculação e efeito micoherbicida de fitopatógenos na germinação de plantas espontâneas

Abstract

The difficulty in managing spontaneous plants is a challenge for farmers in organic production systems. The objective of this work was to evaluate methods of inoculation of fungi with potential mycoherbicide Aspergillus sp., Fusarium sp. and Rhizoctonia sp. on the germination and viability of annoni grass seeds (Eragrostis plana) and bittergrass (Digitaria insularis). For this, the methods of direct contact and immersion of the seeds were compared in experiments repeated three times. The experimental design was completely randomized with four replicates in a factorial scheme (2x4); with factor A two methods of inoculation and factor D three phytopathogens plus the control. The method of contact with Fusarium sp. decreased the percentage of normal seedlings. E. plana. In D. insularis method of contact with Rhizoctonia sp. and the method of immersion with Fusarium sp. reduced in 23 and 29% of normal seedlings, respectively, and increased seed mortality. The results demonstrate that the inoculation method influences the activity of natural pathogens and that Fusarium sp. was efficient in the control of both species. However, it is still necessary to perform additional tests to verify the behavior of phytopathogens in uncontrolled environments, as well as to verify the toxins produced by the fungi involved in the symptoms identified in the target plants.